Safety-clutch for mine-cages.



B. B. ROBERTS.

SAFETY CLUTCH FOR MINE GAGES.

APPLICATION IILBD APR. 29, 1912.

Patented Sept. 2, 1913.

COLUMBIA numouluum co.. WASHINGTON. n c,

BRERETON BURGESS ROBERTS, OF CIMLA, NEAlI-I, \VALES.

SAFETY-CLUTCH FOR MINE-OAGES.

Specification of Letters Patent.

Rntcntcd Sept. 2, 19.11%.

Application filed April 29. 1912. Serial No. 693,906.

To all whom "it may concern:

Be it known that I, Bnnun'ron Bunonss Ronnnrrs, a subject of the King of Great Britain, and a resident of Neath, Vales, whose poSt-otlice address is Park House, Ciinla, Death, in the county of (lrlainorgan, lVales, have invented Improvements in Safety-Clutcl1es for Mine-Cages, Lifts, and the Like, of which the following is a speci- .tication.

This invention relates to automatic safety devices as applied to mine cages, lifts and the like, of the kind in which gripping or scotching members adapted to engage with the guides, but normally restrained from action by the tension of the winding rope, become automatically operative under the action of springs upon the tension being removed through the breaking of the rope.

My invention is chiefly appliealiile to mining cages in which guide ropes are used. Usually each cage is provided with two or more projecting guide-brackets loosely inclosing the guide ropes as the cage is drawn up or let down the shaft. These guide ropes are made of strands of steel wire. They are firmly secured at the top of the shaft, and are kept in a state of tension. The cage is suspended trom the hook or ring of the winding rope by means of chain bridles secured to the four top corners of the cage.

Many devices have been proposed for gripping the guide ropes automatically in the event of the breaking ot' the winding rope and so preventing the :talling ot' the cage. I11 most 0t these the grouping device is adapted to clutch the guide ropes under the action of a spring which is normally restrained by the tension ot the winding rope. In some cases the device is mounted on a supporting plate loosely connected with the cage.

My invention is of the latter class and its advantages consist in an improved form of gripping device in combination with the member or members forming the connection between the supporting plate and the cage.

The accompanying drawings show the invention applied to a cage with one pair of guides and guide ropes.

Figure 1 is an elevation of the upper part of a suspended cage with my automatic gripping device in its retracted position. Fig. 2 a detail in perspective of the collar and its connections. Fig. 3 is a plan view of the invention shown in Fig. 1.

To the top of the cage A centrally projecting upward is fixed a rod 13 oil? sullicient strength to support the weight of the cage and its load it required. The upper part of this rod has a thickencd portion or shoulder (l and above this is a still thicker portion l) forming a head. The rod B before being attached, is pressed down ard centrally through lever operating means in the :torm of a block E which has a hole i large enough to receive the stem but not large enough to admit the shoulder then through a hole (i in a plate ll and linally through a hole I in a central part of the cage root, when it is firmly secured by means of nuts K, the end being threaded for the purpose. The plate Tl is the bed of the automatic gripping device and its cminections. A pair of jaws T1 are pivotally mounted above the carrier or plate T l so as to open laterally under the influence oi a compressed spring N recessed between them. The jaws are raised slightly above the level of the plate taco by means of blocks or steps 0, one at each end (the outer one not shown). il hrough the inner ends of these blocks. and through the plate H are passed bolts N which form the pivots ol' the jaws L and are well secured by nuts or riveting. Over the outer ends of the jaws L is placed a strong bridge or staple l the ends ol which are passed. through the plate ll and riveted beneath. This staple allows snllicicnt lateral play to the jaws Tl but prevents any 'crtical displacement. Before the staple is fixed in position however the plate H, which has a recess or slot ll cut in each end, is placed so that the guide ropes lie loosely within the said slots; the ropes are thus retained in the slots when the staples are fixed. The jaws are conveniently recessed at the part where they grip the guide-rope and the recesses are 'n'e'l'erably rifled so as to tit closely around the wire strands. Sliding collars S are placed over the jaws l and the outer shape of the latter is such that when a collar is slid in an outward direction "it wedges the jaws inward so as Finally to grip the rope. The reverse action allows them to open under the action of the spring 1. The collar 9 is cminecttal by rods U with the top bar V of a rocking Frame with sides V of which the lower bar Y is pivotally mounted on bearings X. The top bar V of the frame is connected with the block E by means of a rod the inner end of which is pivoted within a vertical slot in the side of the block.

The cage A is suspended normally from the ring a of the winding rope b by means of the bridles 0 attached to the lugs (Z of the cage. The block E with its connections including the bed plate H is suspended from the same ring by chains 6 attached to eyes f fixed to the block. The length of these chains is so adjusted that when the cage is suspended the block E is drawn up so as to just butt against the thick part C of the rod B and a slight space is preferably left between the bot-tom of the plate H and the top of the cage. A coiled spring 9 in a state of compression but not strong enough to lift the cage is placed over the shoulder C between the head D and the top of the block E.

The action of the apparatus will now be apparent. \Vhen in a normal state of suspension, the parts arrange themselves as shown in Figs. 1 and 2, the collars S being drawn inward, the jaws L consequently open, the plate H raised above the top of the cage, and the spring 9 compressed. be tween the weight of the cage and the tension of the winding-rope. Instantly upon the snapping of the winding-rope b, the cage and whole apparatus begin to fall; the part which moves downward most quickly however is obviously the block E, owing to the downward push of the spring 9 which is now free from compression, and this acting on the toggle-like arrangement of rods Z U forces the collars S to slide outward and bind the grips L upon the ropes Q, before the cage has had time to fall through an equal space. By the time the weight of the cage comes upon the block, that is when the shoulder C overtakes the block, in doing which it re-compresses the spring 9, the grips are already in position to bear the shock which has been mitigated by the resistance of the spring g, and the only effect will be that the collars S will be driven still farther under the action of the toggles and the binding of the grips be made still more effective; the rifling of the recesses in the jaws L will prevent downward slipping or it may produce a twist in the rope for a short time which will act as a gradual brake; the cage will thus be left suspended by means of the rod B. I may modify the arrangement in various ways. For example the rocking frame W may be dispensed with, by uniting the rods U directly with the rods Z. Also the gripping device may, if preferred, be fixed below the plate H by providing suitable perforations there in for the connecting members. It is obvious that the number of such gripping devices need not be limited to one pair, as another pair could be connected crosswise with the same block, or two supporting rods might be fixed to the top of the cage with two sets of locking gear each engaging a separate pair of guide ropes.

Having thus described my invention what If claim is l 1. An automatic safety device for mine cages, lifts, and the like, comprising guide ropes, a movable plate, a pair of jaws mounted at each end thereof and adapted to grip the guide ropes, slidable collars adapted to cause said jaws to grip said guide ropes, a spring adapted to impel said sliding collars, said spring being normally restrained by tension of the winding rope, a

connection between said movable plate and I the cage consisting of a rod projecting upward from the cage, and passing loosely through the said plate, a block through which said rod also passes, and rods connecting said block with the aforesaid collars, said rod having a shoulder at its upper end to retain said block.

2. An automatic safety device for mine cages, lifts, and the like, comprising guide ropes, a movable plate, a pair of jaws mounted at each end thereof, and adapted to grip the guide ropes, slidable collars adapted to cause said jaws to grip said guide ropes, a spring adapted to impel said sliding collars, said spring being normally restrained by tension of the winding rope, a connection between said movable plate and the cage consisting of a rod projecting upward from the cage, and passing loosely through the said plate, a block through which said rod also passes, rods connecting said block with the aforesaid collars, said rod having a shoulder at its upper end to retain said block, said spring actuating the aforesaid collars being 'mounted near the upper end of said rod, said rod having a head between which and the block, the spring is normally compressed, a ring on the winding rope, and a bridle for suspending said block from said winding rope.

3. An automatic safety device for mine cages, lifts, and the like, comprising guide ropes, a movable plate, a pair of jaws mounted at each end thereof and adapted to grip the guide ropes, slidable collars adapted to cause said jaws to grip said guide ropes, a spring adapted to impel said sliding collars, said spring being normally restrained by tension of the winding rope, a connection between said movable plate and the cage con sisting of a rod projecting upward from the cage, and passing loosely through the said plate, and a block through which said rod also passes, jointed rods connecting said block with the aforesaid collars said rod having a shoulder at its upper end to retain said block.

4;. An automatic safety device for mine cages, lifts, and the like, comprising guide ropes, a movable plate, a pair of aws mounted at each end thereof and adapted to grip the guide ropes, slidable collars adapted to cause said jaws to grip said guide ropes, a spring adapted to impel said sliding collars, said spring being normally restrainet l by tension of the winding rope, a connection between said movable plate and the cage consistiug oi a rod projecting upward from the cage and passing loosely through the said plate, a block through which said rod also passes, jointed rods connecting said block with the aforesaid collars, and rocking frames to assist said rods, said rod having a shoulder at its upper end to retain said block.

5. An automatic safety device for mine cages, lifts, and the like, comprising guide ropes, a movable plate, a pair of jaws mounted at each end thereof and adapted to grip the guide ropes, slidable collars adapted to cause said jaws to grip said guide ropes, a spring adapted to impel said sliding collars, said spring being nm'u'ially restrained by tension of the winding rope, a connect ion between said movable plate and the cage consisting of a rod projecting upward from the cage and passing loosely through the said plate, a block through which said rod also passes, rods connecting said block with the aforesaid collars, said rod} having a shoulder at its upper end to retain said block, said jaws being provided with rillcd recesses adapted to tit closely around the strands of the guide ropes.

(3. In combination, a cage or lift, suitable tlcxible guides thereit or, a winding cable connected with the rage, a carrier, jaws mounted on said carrier and embracing said guides, lever mechanism mounted on said carrier for operating said jaws, means carried by said cable and connected with said lever mechanism to support the carrier and operate said jaws to grip but not; kink said guides, and a spring device connected with said means and cage and adapted to operate upon breakage of said cable, substantially as described.

7. An automatic safety device for mine cages and the like comprising a guide rope, a pair of movable opposed jaws embracing said rope and adapted to grip said guide rope, a slidable collar embracing said jaws and adapted to grip said guide rope, a spring adapted to move said collar into the position to operate said jaws, said spring being normaltv restrained by tension of the winding rope, operating connect-ions between said spring and said collar. and conncctions between said spring and winding rope adapted to normally restrain the same.

B'ltllltilltlN BURGESS ROBERTS.

\Vitnesscs Aaron]: S. T. Lucas, Lnnwisnrx Ba'rour.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iatents. Washington, I). C. 

